Not applicable.
Not applicable.
Not applicable.
The invention relates to an alternative or additional solution to dental surgeons and stomatologists to remove individual crowns, bridge supports and other prostheses sealed on natural teeth or implants.
The purpose of this invention is to give an alternative or additional solution to dental surgeons and stomatologists to remove individual crowns, bridge supports and other prostheses sealed on natural teeth or implants. Most existing solutions are either of complex implementation, or costly because they cause, on one hand, destruction of the crown (4), and on the other hand, significant wear of the burs and fatigue of the rotary instruments. Furthermore, this is an unpleasant even painful operation for the patient.
It is first to be noted that:
although, in practice, a tooth or an implant is never vertical in the strict sense of the term, for reasons of clarity in the explanations, the verticality reference will be the vertical axis of the tooth (F) or of the implant, as shown in FIGS. 16, 17 and 18;
FIG. 16 shows a cross-section of the tooth along the sagittal plane while FIGS. 17 and 18 show a cross-section of the tooth along the frontal plane; and
all figures, embodiments and applications are described based on a prosthesis sealed onto a natural or reconstructed stump (3). However, this invention can perform the same function whenever the stump (3) is prosthetic, especially in the field of implantology. As a convention, the prosthetic system that fits on the implant and on which the crown is set (4) shall be designated as the prosthetic stump (3).
In the field of dental crown removal, one of the means used has been the instrument patented in 1982 under the name of dental instrument designed for the removal of crowns and pivot teeth (Publication No. 2 522 494, National Publication No. 82 03435, date of filing: Mar. 2, 1982). It consisted primarily of a grip and a shank with its front part bent back. That tool and the method used offered the advantage of causing a lever effect between the stump (3) and the crown (4) while sparing the gum and thus enabling to recover the crown (4) whenever the operation was successful. However, the shapes and dimensions of the instrument, and the method used, made it so that the couple of forces generated to achieve the lifting of the crown (4), took place on one hand on the occlusal surface of the stump (3), and on the other hand at the top of the notch (1) made in the face of the crown (4). However, if the seating of the occlusal surface of the stump (3) was located in the vertical axis (F) of the tooth, the force applied on the wall of the crown (4) was then a movement offset in relation to the vertical axis (F) of the tooth. This resulted in a lateral force that was harmful to the dent or implant.
Another device published under reference EP 0 399 237 has this same disadvantage of generating a tilting movement of the prosthesis in relation to the stump because of the actuation of flat and protruding shapes.
On the contrary, this invention makes it possible to achieve an even couple of forces, limiting or eliminating any lateral force because the latter is in an axis that coincides fully or almost fully with the vertical axis (F) of the tooth or implant.
This invention consists of an instrument containing an indented intermediate part (C) and a working part (D). Inserted into a groove (2) made beforehand by the practitioner, the working part (D) is designed to generate a couple of forces roughly in the vertical axis (F) of the tooth or implant between the occlusal faces of the stump (3) on one hand, and the basal surface of the crown (4) on the other hand, thus causing the removal of the crown (4). Until the crown (4) is unsealed, the shapes and dimensions of the indented intermediate part (C) enable it not to hinder the lifting of the notched sidewall of the crown (4) and not to apply any lateral forces on the crown (4).